Internal-combustion engine



H. J. POCOCK INTERNAL COMBUSTION ENGINE Filed March 8. 1922 March 25 1924.

Patented Mar, 25, 1924.

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DON, ENGLAND.

ENGLAND, ASSIGNOR OF ONE-THIRD TO ACHILLE RIVARDE, BOTH 0F LON- INTERNAL-COMBUSTION ENGINE.

Application filed March 8, 1922. Serial No. 541,984.

T 0 .all whom it may concern:

Be it known that I, HORACE JAMES POGOCK, a subject of the King of Great Britain, residing at 13 Gladys Road, Kilburn, in the county of London, England, have invented certain new and useful Improvements in or Relating to Internal- Combustion Engines, of which the following is a specification.

This invention relates to internal combustion engines of the type in which a rotating ported sleeve is provided inside the cylinder, which sleeve controls the inlet and exhaust. The chief object of the present invention is to simplify the construction of an engine of this type and to obtain a more rapid opening and closing of the inlet and exhaust ports with an increased dwell throughout the inlet and exhaust strokes of the piston.

The improvements are illustrated'in the accompanying drawings, in which Figure 1 is a half section and half elevation of a single acting cylinder embodying this invention.

Figure 2 is a transverse section through the cylinder, piston and rotating sleeve.

Fi ures 2 and 2 are detail views showing the form of the cylinder ports.

Figures 3 and 4 are elevations of the pistonshowing a piston with inlet and outlet ports and Figure 5 is a half vertical section and half elevation and Figure 6 a cross section v of a. double acting engine.

Referring to the single acting engine shown in Figures 1 to 4, A is the cylinder having an inlet port a and an exhaustport (4' arranged at-an angle to each other as shown in Figure 2. B is the rotating sleeve having a pair of ports I) placed diametrically opposite each other and at the same level as the cylinder ports. 0 is the piston withinlet and exhaust ports a and c in alignment with the corresponding cylinder ports.

The rotating sleeve is engine driven, for example, through the toothed ring 6 at the lower edge, which extends beyond the end of the cylinder A. The sleeve occupies the outer or lower portion of the cylinder, slightly recessed to the, thickness of the sleeve which meets at its upper end the cylinder shoulder a the inner surface of the sleeve and upper portion of the cylinder being flush.

The piston C is of trunk type, the connecting rod D being attached to a gudgeon pin 02 secured inside the piston near its in ner end, the'pin d extending symmetrically between the piston ports 0, c as shown more clearly in Figure 2.

The piston Wall is provided with the inwardly projecting recesses c and 0 forming inlet and outlet channels opening the respective ports 0 and 0' through the end of the piston intothe combustion space E of the cylinder. The ports or openings 0, c in the piston wall, corresponding to the inlet and exhaust ports of the cylinder, are made of peculiar shape in order to give maximum effective port area for minimum area of aperture, allowing for the combined reciprocating and rotary movements of the piston and sleeve respectively, the central portion of the ports 0, a being of maximum width corresponding to the point of maximum uncovering of the cylinder ports a, a by the ports I) of the rotating sleeve B.

Dealing first with the inlet port a of the piston, the lower edge 0 is longitudinal, that is, parallel to the edge of the sleeve port 6, so that when the piston is at the upper end of its stroke and the port 1) begins to open the inlet as rapid an opening is obtained through the piston as can be allowed by the sleeve port. The opposite ed e c of the piston port slopes upwardly to a out the middle of the port so as to follow the forward corner of the sleeve port 6 as the piston moves down and the port turns. This slope of the edge 0 reduces the amount of the piston wall which has to be cut away without reducing the effective port area. The vertical edge 0. terminates at the backwardly sloping edge a which causes the port a to expand towards the middle where it has maximum width, contracting again towards the upper end of the piston by the formation of the forwardly sloping edge 0 which follows the upper corner of the sleeve port during the latter part of the downward move- -to reduce to a minmum the cut away part of the piston wall while providing a maximum area of passage for the gases. At the upper end of the port 0 the port branches at c to the side to provide an auxiliary inlet beyond the bottom dead centre of the piston stroke so that the inlet for the gases is continued through a narrow opening to about, sav, 32 beyond the dead centre.

The exhaust port a of the piston is very similar to the inlet port 0, the vertical edge 0 corresponding to the edge 0* of the inlet and the opposite sloping edge 0 corresponding to the edge 0. The upper vertical edge 0, however, extends straight down to the upper end of the sloping edge a so that there is no recessed portion at this side of the port. The sloping edges 0 and 0 at the opposite side are similar in position to the edges 0 and 0 of the inlet port. The exhaust port is also provided with the side extension or branch 0 corresponding to the extension 0 of the inlet port but of somewhat greater depth, the object of this extension being to give an extra area of opening at the beginning of the exhaust.

The inwardly projecting recesses and 0 do not follow the outline of the inlet and exhaust ports-0 and 0 except at the lower shown in the detail views Figures 2* and 2" a corner portion a being cut from the corner of the inlet port a to correspond to the branch 0 of the piston port while a similar corner a is cut away at the edge of the exhaust port a to form an auxiliary opening corresponding to the branch 0 of the piston exhaust port. The extensions a and (1* of the cylinder ports are formed by chamfering the recesses atthe corners of the respective ports.

The engine follows the usual cycle of a four stroke engine, the rotating sleeve B, which is shown with a pair of ports I), turning at one-fourth engine speed, each port 6 as the sleeve turns opening the inlet and exhaust ports in succession, the position and area of the sleeve of the cylinder ports being determined so as to give the desired timing of the inlet and exhaust. When one of the ports I) begins to open the inlet port a the piston C is at about the upper end of its,

stroke and as it descends the port 6 begins to sweep across the vertical edge 0* of the piston inlet port 0. As the piston descends the inlet opening rapidly increases in area. the lower corner edge of the sleeve port 1) as it travels forward following approximately the sloping edge 0 of the piston port as the piston descends. The full inlet area is reached about themiddle of the piston stroke and this decreases as the sleeve port moves forward, the upper corner of the port following approximately the edge 0 of a of the piston and cylinder exhaust ports,

giving exhaust immediately the piston nears the outer end of the working stroke. The exhaust continues throughout the return stroke of the piston and the maximum exhaust port area is reached about the middle of the stroke. Immediately after the end of the stroke the admission of the fresh charge begins and the cycle is repeated.

In the double acting engine shown in Figures 5 and 6 the engine operation is on the lines already described but the piston C is of double trunk form and is made in two parts, the upper one of which is screwed upon the central tubular stem 0, while the lower one terminatesin the tubular piston rod 0 passing through the gland a", provision being made for water circulation through the piston and piston rod, by means of the inner tube 0 and apertures 0 The rotating sleeve B is placed at the middle of the double acting cylinder A and the drive is through the toothed ring 6 lriven by the pinion F on the engine driven shaft The form of each half of the double act-ing piston C is similar to that of the single actingpiston C already described and the ports 0 and 0 are similarly formed and arranged, the two halves of the piston C having their ports inverted so as to correspond to the opposite movements in the twoends of the :ylinder. The cylinder is provided with two pairs of inlet and exhaust ports a and a, one pair serving for the upper end and the other pair for the lower end of the cylinder. The sleeve ports I) for the upper and lower ends of the cylinder are relatively displaced so as to uncover the cylinder inlet and exhaust ports at diflerent times, corresponding to the alternating outward and inward strokes of the piston for the opposite ends of the cylinder.

What I claim and desire ti) secure by Letters Patent of the United States is 1. In an internal combustion engine, an engine cylinder having inlet and exhaust ports, an engine driven rotatable sleeve within said cylinder having a controlling port adapted to register successively with thesaid inlet and exhaust ports, and a trunk piston having a pair of longitudinal ports one corresponding in position to the said inlet port and the other to the said exhaust port of the cylinder, which piston ports expand in width from both ends towards the middle, the piston being provided also with corresponding internal channels opening the said ports through the end of the piston.

2. In an internal combustion engine, an engine cylinder having inlet and exhaust ports, an engine driven rotatable sleeve within said cylinder, having a controlling port adapted to register successively with the said inlet and exhaust ports, and a trunk piston provided with a pair of internal longitudinal channels and a pair of longitudinal ports in its side walls one corresponding in position tothe said inlet port and the other to the said exhaust port of the cylinder, each of the said piston ports having a rearward sloping edge at the upper and lower ends and opposite longitudinal edges so that the ports expand in width towards the middle, the channels inside the piston leading from the said ports through the inner end of the piston.

3. In an internal combustion engine, an engine cylinder having inlet and exhaust ports, which ports are formed with a lateral extension at the inner corner, an engine driven rotatable sleeve within said cylinder having a controlling port adapted to registei successively with the said inlet and {exhaust ports, and a. trunk piston having a pair of longitudinal portscorresponding in position to the said cylinder ports, which piston ports expand in width from both ends towards the middle and are each provided with a lateral extension at the inner corner corresponding to the extensions of the cylinder ports, the piston being provided also with corresponding internal channels opening the said ports through the end of the piston.

HORACE JAMES POCOCK. 

